Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1966 Oct;186(3):632–662. doi: 10.1113/jphysiol.1966.sp008060

The time and voltage dependence of the slow outward current in cardiac Purkinje fibres

R E McAllister, D Noble
PMCID: PMC1395918  PMID: 5972158

Abstract

1. In normal Tyrode solution the initial inward sodium current which is produced in Purkinje fibres in response to a sudden depolarization is followed by a very slow change in current in an outward direction. The magnitude and speed of onset of this slow change both increase with the strength of the depolarization.

2. On repolarization, a transient outward current is observed (Deck & Trautwein, 1964). The initial magnitude of this outward current also increases with the strength and duration of the preceding depolarization, with a time course similar to the time course of the slow change in current during depolarization.

3. Evidence is presented for the view that the slow change in current during depolarization represents the onset of delayed potassium rectification and that the decline in outward current following repolarization represents its decay.

4. Removal of sodium ions greatly increases the threshold of the slow outward current. In the presence of sodium ions 15 mV depolarization is sufficient to produce an appreciable current. In the absence of sodium ions at least 50 mV depolarization is required and, in some fibres, no delayed rectification is observed even when the membrane potential is made positive.

5. Prolonged depolarization of the membrane by outward current changes the quiescent membrane potential in a positive direction. This change in potential is attributed to an accumulation of potassium ions in a space immediately outside the cell membrane, which equilibrates slowly with the extracellular fluid. It is shown that this effect is very small during depolarizations of the magnitude and duration of the normal action potential.

6. It is concluded that the results are consistent with the view that repolarization of the Purkinje fibre action potential is initiated by a slow increase in K conductance similar to, but much smaller and slower than, that observed in nerve fibres.

Full text

PDF
632

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adrian R. H., Freygang W. H. The potassium and chloride conductance of frog muscle membrane. J Physiol. 1962 Aug;163(1):61–103. doi: 10.1113/jphysiol.1962.sp006959. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Brady A. J., Woodbury J. W. The sodium-potassium hypothesis as the basis of electrical activity in frog ventricle. J Physiol. 1960 Dec;154(2):385–407. doi: 10.1113/jphysiol.1960.sp006586. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CARMELIET E. E. Chloride ions and the membrane potential of Purkinje fibres. J Physiol. 1961 Apr;156:375–388. doi: 10.1113/jphysiol.1961.sp006682. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. CARMELIET E. Influence du rythme sur la durée du potentiel d'action ventriculaire cardiaque. Arch Int Physiol Biochim. 1955 Jun;63(2):222–232. doi: 10.3109/13813455509150410. [DOI] [PubMed] [Google Scholar]
  5. DECK K. A., KERN R., TRAUTWEIN W. VOLTAGE CLAMP TECHNIQUE IN MAMMALIAN CARDIAC FIBRES. Pflugers Arch Gesamte Physiol Menschen Tiere. 1964 Jun 9;280:50–62. doi: 10.1007/BF00412615. [DOI] [PubMed] [Google Scholar]
  6. DECK K. A., TRAUTWEIN W. IONIC CURRENTS IN CARDIAC EXCITATION. Pflugers Arch Gesamte Physiol Menschen Tiere. 1964 Jun 9;280:63–80. doi: 10.1007/BF00412616. [DOI] [PubMed] [Google Scholar]
  7. Daly I. de B., Clark A. J. The action of ions upon the frog's heart. J Physiol. 1921 Mar 15;54(5-6):367–383. doi: 10.1113/jphysiol.1921.sp001938. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dudel J., Peper K., Trautwein W. The contribution of Ca++ ions to the current voltage relation in cardiac muscle (Purkinje fibers). Pflugers Arch Gesamte Physiol Menschen Tiere. 1966;228(3):268–281. [PubMed] [Google Scholar]
  9. FALK G., FATT P. LINEAR ELECTRICAL PROPERTIES OF STRIATED MUSCLE FIBRES OBSERVED WITH INTRACELLULAR ELECTRODES. Proc R Soc Lond B Biol Sci. 1964 Apr 14;160:69–123. doi: 10.1098/rspb.1964.0030. [DOI] [PubMed] [Google Scholar]
  10. FATT P. AN ANALYSIS OF THE TRANSVERSE ELECTRICAL IMPEDANCE OF STRIATED MUSCLE. Proc R Soc Lond B Biol Sci. 1964 Mar 17;159:606–651. doi: 10.1098/rspb.1964.0023. [DOI] [PubMed] [Google Scholar]
  11. FRANKENHAEUSER B. A QUANTITATIVE DESCRIPTION OF POTASSIUM CURRENTS IN MYELINATED NERVE FIBRES OF XENOPUS LAEVIS. J Physiol. 1963 Nov;169:424–430. doi: 10.1113/jphysiol.1963.sp007268. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. FRANKENHAEUSER B., HODGKIN A. L. The after-effects of impulses in the giant nerve fibres of Loligo. J Physiol. 1956 Feb 28;131(2):341–376. doi: 10.1113/jphysiol.1956.sp005467. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. FRANKENHAEUSER B. Potassium permeability in myelinated nerve fibres of Xenopus laevis. J Physiol. 1962 Jan;160:54–61. doi: 10.1113/jphysiol.1962.sp006834. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Fozzard H. A. Membrane capacity of the cardiac Purkinje fibre. J Physiol. 1966 Jan;182(2):255–267. doi: 10.1113/jphysiol.1966.sp007823. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. HALL A. E., HUTTER O. F., NOBLE D. Current-voltage relations of Purkinje fibres in sodium-deficient solutions. J Physiol. 1963 Apr;166:225–240. doi: 10.1113/jphysiol.1963.sp007102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. HODGKIN A. L., HOROWICZ P. The influence of potassium and chloride ions on the membrane potential of single muscle fibres. J Physiol. 1959 Oct;148:127–160. doi: 10.1113/jphysiol.1959.sp006278. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. HODGKIN A. L., HUXLEY A. F. Currents carried by sodium and potassium ions through the membrane of the giant axon of Loligo. J Physiol. 1952 Apr;116(4):449–472. doi: 10.1113/jphysiol.1952.sp004717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. HUTTER O. F., NOBLE D. Anion conductance of cardiac muscle. J Physiol. 1961 Jul;157:335–350. doi: 10.1113/jphysiol.1961.sp006726. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. HUTTER O. F., NOBLE D. Rectifying properties of heart muscle. Nature. 1960 Nov 5;188:495–495. doi: 10.1038/188495a0. [DOI] [PubMed] [Google Scholar]
  21. LUTTGAU H. C., NIEDERGERKE R. The antagonism between Ca and Na ions on the frog's heart. J Physiol. 1958 Oct 31;143(3):486–505. doi: 10.1113/jphysiol.1958.sp006073. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. NOBLE D. A modification of the Hodgkin--Huxley equations applicable to Purkinje fibre action and pace-maker potentials. J Physiol. 1962 Feb;160:317–352. doi: 10.1113/jphysiol.1962.sp006849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. NOBLE D. Cardiac action and pacemaker potentials based on the Hodgkin-Huxley equations. Nature. 1960 Nov 5;188:495–497. doi: 10.1038/188495b0. [DOI] [PubMed] [Google Scholar]
  24. Noble D. Applications of Hodgkin-Huxley equations to excitable tissues. Physiol Rev. 1966 Jan;46(1):1–50. doi: 10.1152/physrev.1966.46.1.1. [DOI] [PubMed] [Google Scholar]
  25. ORKAND R. K., NIEDERGERKE R. HEART ACTION POTENTIAL: DEPENDENCE ON EXTERNAL CALCIUM AND SODIUM IONS. Science. 1964 Nov 27;146(3648):1176–1177. doi: 10.1126/science.146.3648.1176. [DOI] [PubMed] [Google Scholar]
  26. Reuter H. Strom-Spannungsbeziehungen von Purkinje-Fasern bei verschiedenen extracellulären Calcium-Konzentrationen und unter Adrenalineinwirkung. Pflugers Arch Gesamte Physiol Menschen Tiere. 1966;287(4):357–367. [PubMed] [Google Scholar]
  27. TRAUTWEIN W., KASSEBAUM D. G. On the mechanism of spontaneous impulse generation in the pacemaker of the heart. J Gen Physiol. 1961 Nov;45:317–330. doi: 10.1085/jgp.45.2.317. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. WEIDMANN S. Effect of current flow on the membrane potential of cardiac muscle. J Physiol. 1951 Oct 29;115(2):227–236. doi: 10.1113/jphysiol.1951.sp004667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. WEIDMANN S. Effects of calcium ions and local anesthetics on electrical properties of Purkinje fibres. J Physiol. 1955 Sep 28;129(3):568–582. doi: 10.1113/jphysiol.1955.sp005379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. WEIDMANN S. Shortening of the cardiac action potential due to a brief injection of KCl following the onset of activity. J Physiol. 1956 Apr 27;132(1):157–163. doi: 10.1113/jphysiol.1956.sp005510. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES